Hundreds of women who hoped to changed their lives say they were instead scammed by fitness trainer Brittany Dawn, who they say took their money and then failed to deliver promised exercise and diet plans.

Dawn, whose real name is Brittany Davis, is a Dallas-based workout guru who has more than 840,000 followers on Instagram and YouTube.

Since 2014, she has been selling health and fitness plans for as much as $300 each. But her enterprise is in shambles after scores of women came forward to claim they did not receive what they paid for and that Dawn deleted complaints posted to her social accounts and then blocked the women from her accounts.

"So many girls were used and abused," said Angie Bullock, 28, a stay-at-home mom in Oregon. "She preys on women who are insecure and vulnerable. She preys on people who have eating disorders ... These girls need help."

Bullock said she purchased a $92 plan in 2015 that "was supposed to be individualized to me, with cardio and a diet tailored to me." She also was supposed to receive weekly check-ins with Dawn to discuss her progress and adjust her workouts and diet if needed, Bullock said. Instead, "she took my money, gave me a plan then never contacted me again."

The diet plan was extremely generic, she said, containing only lists of food and how many grams of fat, protein, and carbs should be eaten daily. "I know what vegetables are," Bullock said. Her workout was for two hours a day, "which is insane," Bullock said. She would later find out, by talking with other customers, that the women were all given the same plan, she said.

Bullock reached out several times, leaving messages on Dawn's Instagram account, but received no response, she said. Then she was blocked from all of Dawn's social media accounts, she said. She asked for a refund, but didn't get one, she said. Eventually, she gave up.

But she continued following Dawn's Instagram account, which is full of photos of the 26-year-old Texas woman working out with weights, advertising fitness clothes, and sitting in her Range Rover. In before-and-after images, she is shown being transformed into a noticeably thinner and more toned woman with frosted hair.

Bullock admired her. "She had everything and anything she wanted," Bullock said. That is the entire point of being an "influencer" on Instagram — a description that covers personalities such as Kim Kardashian. "You want that lifestyle," Bullock said. "You want to look like them. They influence your life in every way."

Then she noticed a post on Dawn's Instagram account accusing the fitness influencer of scamming her customers. The post was immediately deleted, Bullock said. That led her to do a Google search of complaints against Dawn, which led in turn to a Facebook page titled "Brittany Dawn Fitness Complaints."

There were 200 women belonging to that group when Bullock joined four years ago. They all had similar stories. Each had spent from $100 to more than $300 on diet and exercise plans that promised to be designed specifically for their individual bodies, they said.

What they received was the same plan as everyone else, they said, and after a few brief, initial contacts, Dawn stopped responding to them, they said.

Now there are more than 4,600 members. In the past few months, the outcry from women who claim they were bilked has grown exponentially louder, with alleged victims contacting media outlets, filing complaints with the Better Business Bureau and contacting advertisers on Dawn's social media accounts.

Dawn said she never intended to harm anyone. She issued an apology on YouTube in a tearful, Feb. 6 video. "I ran too fast for one person," she said. "At times it got extremely overwhelming, and I took on more than I should have and for that, I take full responsibility and I am sorry."

She is no longer selling fitness plans, she said. She claims to have received death threats.

In an email to InsideEdition.com, Dawn wrote, "I know that I have destroyed my reputation through inaction and lack of communication. I own it and am attempting to make things right the best I can." She has begun issuing refunds on a "case-by-case basis," she said.

Her public apology means little to the women who paid her to help transform their lives.

"You're not the victim here," one person said in the video's comments section. "The minute you realized you couldn't deliver what you promised, you refund people. Period. End of story. There are a lot of business owners who create their own content, provide their own customer support, do their own finances, etc. They still deliver what they promised and what people paid them for."

Dawn's former clients compare her enterprise to the doomed Fyre Festival, a failed luxury music festival in the Bahamas that promised exclusive accommodations and a high-powered lineup of more than 30 groups including Pusha T, Tyga, Major Lazer and Disclosure.

Instead, the 2017 event ended up being a rained-out, public relations disaster with no accommodations and little food and water. There also was no concert.

In October, event organizer Billy McFarland, 26, was sentenced to six years in federal prison for fraud. He had earlier pleaded guilty to wire fraud charges in connection with the festival and to other fraud charges related to a separate scam.

"You have a responsibility to be a responsible marketer," New York City management crisis and public relations executive Ronn Torossian told InsideEdition.com. If you promise a service, you must deliver that service, he explined. "You can't claim that you didn't know better."

Dawn's brand "will never recover," he said, calling her public apology "inauthentic" and "disingenuous."

Bullock said she finally received a full refund on Thursday, after four years of asking for one.

The Facebook group is now documenting their experiences with Dawn in an effort to compile a class-action suit. They are working with a Los Angeles attorney. Members have also contacted the Fair Trade Commission and the IRS, asking for investigations into Dawn's business practices.

"What really upsets me is I continually see women posting about wanting to have her life and look like her and be like her," Bullock said. "She is one of the top influencers on Instagram. A lot of women are looking up to someone who has a serious mental health issue."